Symptomatic ossification of the ligamentum flavum at the lumbar spine: a retrospective study

A retrospective study on 9 patients treated for ossification of the ligamentum flavum (OLF) at the lumbar spine.

To evaluate the clinical and radiologic findings as well as the postoperative results of the patients.

Ossification of ligamentum flavum (OLF) in the lumbar region causing neurologic impairment is a rare pathologic entity described mainly in Japanese literature. The present study represents the largest surgical series of European patients with OLF at the lumbar spine.

A retrospective study of 9 consecutive patients was conducted between 2000 and 2005. The clinical status was evaluated according to the Japanese Orthopedic Association scale. Potential associated disorders were also recorded. Diagnosis in each case was established using computed tomography and magnetic resonance imaging. Whole-spine magnetic resonance imaging was routinely used in order to reveal possible coexisting spinal lesions. Pathologic confirmation was available in all cases.

Radicular pain was the most common presenting symptom. Myotomal weakness was found in most of the cases. A majority of our patients had lesions located at the L3-L5 levels. Thoracic OLF was recorded as a spinal coexisting ossified lesion. Surgery led to neurologic improvement with a statistically significant increase in the Japanese Orthopedic Association score (P = 0.007). The median recovery rate was 91.60% +/- 43.85%.

It is possible that OLF is underreported in the Greek population. Surgical treatment is important in order to improve functional outcomes.